1, you didn't say anything about SLI. 2, I think you might need a bit more then 850W for that. Those GTX590s are 350ish watt parts, so two in SLI will be around 700W(ish). Add in another 100+ for your CPU, and you won't have enough. For SLIing the GTX590, most grab 1kW PSUs.
In that case I stand by my post. If you plan on buying a new PSU later, there is no point in buying that 850W. A good quality 650W should do fine. XFX's 650W or Antecs 650W green come to mind, or Antecs EA750. Any of those should be good quality PSUs that can run a single GTX590 without breaking the bank.
I'd change that psu, but someone else is paying for it, and can't change it now. That's not a big problem though, it's fine.
No need to worry about hard drives. I already have a 1.5TB 7200RPM HDD, from my current computer. By the end of this year(Christmas), i will get another 2TB hard drive. 1.5TB is nothing for me. I have countless BluRay movies purchased, and most of them are 10GB or more (each). So, apparently, i need much space.
Not to talk about games. I might get a SSD drive next summer. I don't really care about how fast the access is, i care having enough space for all my files.
I'm sorry, but you seem like someone more interested in gloating then wondering about his machine. "someone else is buying it"? You picked the second fastest CPU and arguably the fastest video card? If its not a "good gaming rig", what could you do to make it faster? The rig will be fine, I wouldn't sweat it.
Yes, at first, i was not sure of what to get. I wasn't even thinking of buying a 590 at that time. I picked a psu, which looked quite good to me, since it's a 80 plus gold certified.
Now, i may buy another gtx 590 in the future-i may not. But i am not changing this psu. I'll actually pay 1/4 of the original price, because a friend works in the store i'll buy it from. I can't tell him "NO get me another psu because i'm full of uncertainty of what im gonna do in the future".
As i said, you should not worry about the psu, and i shouldn't worry either.
Was firstly aiming for the i7 2600k. But when i read that i7 has almost the same performance as i5 in gaming, then i changed my mind. And i'm going to spend the money i saved from i7 for the 590.
I don't want the best desktop ever, i just want something decent i can certainly enjoy maxed out games on.